Process for the manufacture of 1-amino-4-(4&#39;-hydroxy)-phenylamino anthraquinones



Patented Oct. 7, 1941 UNITED 2,258,551 I C E PROCESS FOR THE'MANUFACTURE OF 1- AMINO 4 (4'-HYDROXY) -PHENYLAMINO ANTHRAQUINONES PaulGrossmann, Binningen, Switzerland,assignor to the firm Society ofChemical Industry in Basie, Basel, Switzerland h No Drawing. ApplicationNovember, 24, 1939, Se-

rial No. 306,033. In Switzerland November 29,

It has been found that l-aminol-i y-hydroxy)-phenyl-amino anthraquinonesoi V the general formula V a o I N-R in which R signifies hydrogen or analkyl, cycloalkyl, aralkyl, or aryl radical and R1 denotes an aromaticnucleus of the benzene series substituted by an OH-group in the4-position, are obtained in a very simple manner and in a pure state ifproducts of the'general formula in which R has the meaning given aboveare allowed to react with l-aminoi-hydroxyben- .30

zenes in the presence of boric acid, it required in the form of itsanhydride, and a diluent selected fromthe group; consisting of cyclicalcohols, cyclic tertiarybases and phenols, such as hols-this termincluding cresols-and similar products, at temperatures lying between 80and 200 (1., preferably at temperatures between 100and150C. Y Thesuccess of this method ofworking, which is of great techincal'importance, 'is'surprising, on account of the fact that the l-amino-ihydroxybenzenes, in contrast to other aromatic amines, such as aniline,para-toluidine, parachloraniline, etc., do not react smoothly accordingto the methods usually adapted for the introduction of phenylaminogroups into the alpha position of the anthraquinone nucleus, forexample, by heating the bases with cc-h5t10- ,cyclohexanol, pyridine,dimethylaniline, phe'- 3.5

genanthraquinones or with u-methoxyanthraquinones. Also, other valuablemethods, as, for example, the condensation of leuco-lzi-diaminoanthraquinones with 1 mol of a l-amino-lhydroxybenzene, do notgive-very satisfactory results as regards yield andpurityof the reactionproduct. a I

Furthermore, the smooth working of the reaction was not to be foreseen,since other aromatic amines, such as, for example, 1-amino-3-hy- 4Claims. c1, 2co ss0).

droxybenzenes, will not permit of condensation Example 1 12 parts ofdried boric acid and 14 parts of l-amino i-hydroxybenzene are mixed into40 partsof cyclohexanol, and then 24 parts of 1-aminol-hydroxy-anthraquinone are added while stirring atl20 C. Themixture is heated at C. for about 5 hours with further stirring andis-then allowed to cool to about 7 0 (3., when '60.. parts of methylalcohol are added: the whole is then cooled to room temperature andfiltered. The filtrationresidue is washed out with methyl alcohol andwater, and the 1-amin0+4-(4'-hydroxy)-phenylamino-anthraquinone formedis obtained invery good yield. Dried boric acid may be replaced by boricacid which has been rendered anhydrous by melting. The reaction may alsobe carried out at a higher temperature, further, for example, even atthe boiling point of the cyclohexanol.

An analogous procedure is adopted with other products of the generalformula Example 2 120 parts of 1-amino-4-hydroxyanthraquinone, togetherwith parts of para-aminophenol and 18 parts of boric acid which has beendehydrated by melting are heated in 2'50 parts of crude cresol for 2hours at 120 C. with stirring, The mixture is then cooled down to about95 C., and a lukewarm mixture consisting of 300 parts caustic soda of40% strength, 500 parts of water and 125 parts of sodium bisulphitesolution of 40% strength is added to the melt with further stirring.This mixture is then cooled down to about 25 0., and the dyestuff, whichhas crystallized in beautiful needles is filtered oil and Washed withwater until the wash-water is seen to be colourless. ,The1-amino-4-(4-hydroxy)-phenylamlnoanthraquinone obtained is very pure,

.thraquinone or By raising the temperature of reaction,'for example, to180 0., the, period of reaction may be shortened. The use of atemperature which is too high may, however, prove disadvantageousasregards the purity of the end product.

Example-"3 15.7 parts of 1-hydroxy-4-phenylaminoanthraquinone, togetherwith 4 parts "of dried *boric acid and 8 parts of 1-amino 4hydroxyben2ene, are heated in 30 parts of cyclohexanol at 150' C. withstirring until the"colour'of thefsolution no longer continues toturn'green'er. When this point is reached, the mixture is allowed to:cool

down to 70 C'., 60 parts of ethyl alcohol are added and the whole isfiltered and the -residue is washed with ethyl alcohol and water.I-iph'IlYlamino 4 ('4-hydroxy) -;-phenylaminoanthra'qui- 'none isobtained in good i yield rand a good zstat'e of purity.

In 1 an analogous ima'nner, compounds :such as 1- 3"-= methyl)plienylam'ino =-"4 -"(4"- hyaroxw phenylaminoanthraquinone, 1 'Q mthOXy)phenylamino 4 -(4' hydroxy)-phenylaminoan- 1- vi -amino)-.phenylamino-4- C4 hydro'xy) -'phenylaniindanthraquinone or '1-(3'-hydlr0Xy) ph enylamino 4 (4"'-ihydro:iy) phenylaminoanthraquinonemay be obtained from N-arylated 1-amino-4-hydroxyanthraqui- Here alsoboric* acid anhydride*may beiused in place cfboric acid:cyclohexanolmay'be replaced by :pyridin'e, dimethylaniline, phenolspsuchas phenol itselfor cresolst It may a1-SQ m-vepre'raabletowork in closedvessels.

What I clai-misz 1, Process-for the manufacture"of l-anrino l- (=4'hy'droxy) phenylalni'nb anthraquinones f thegeneral formula 7 wherein Rstands for a member of the group consisting of hydrogen atoms, alkylandcycloalkyl-, and aralkyl- 'and aryl radicals of the benzene-series, andBy means an aromatic nucleuspf the benzene series substituted by an Oflgroup in the 4-position,--comprising causing 'l-amino-4- hydroxybenzenes'to react in presence of a condensing agent selectedfrom the groupconsist- {4-hydro y)--phenylamino anthraquinones of the *general formulawherinRiliasithe aboveidentified meaning.

3. Process -for the "manufacture of l-aniinol- (4'-hydroxy)-phenylaminoanthraquinones of the general formula I L11 wherein iR stands in wemember or -tlre group consisting @of hydrogen-atoms, alkyl and cycle:alk-yl-., and earalkyland -:aryl :r-ad-icals --of the :51 bengzeneseries fandRnmeans -an aromaticvnucleus ing of boric acid andb'oric-=acid 'anhydride, and

0f a' diluent-selectedfrom-'the 'group consisting; of 1 cyclic alcohols,cyclic tertiary-bases and phenols, at temperatures-between 80 and --200(3., with products of the general formula whereinR has the aboveidentified-meaning.

2. Process -for-the--manufacture of -1 a-mino-4,-

of the benzene --series 'si.il: stituted -*by an .OH- group in -theA-pos-ition, comprising mausing :L-am-ino-4-hydroxybenzene to -react inpresence of a condensing agent selected from :the :groupconsistingaofboric acidand-boric acid anhydride, and :of-a Tphenolas;dilue nt, atytemperatures between I and-200 C., -v'vith-sproduetsof-the general formula Wher'jinRhais theabove identifiedmeaning.

"4. Pir'oc'e'ss "for the 'manufacture of lemme-"4- ''(4 hydroxy)-p'he'nylamino anthraquinone,- com- 'zpr g cal'ising l-aminoflhydroXy-bn'zene' to react inthe presence"of= boric acid L'anhydrid'eia'nd phenols, at temperatures above 80 C. .butmot exceeding my' c flonl-amino 4-hydroxyanthia- -nuinone.

PAUL 'GROSSMAN' 'N.

DISCLAIMER 2,258,551.Paul Grossmann, Binningen, Switzerland. PROCESS FORTHE MANU- FACTURE OF 1-AM1No-4-(4-HYDR0XY)-PHENYLAMIN0 ANTHRAQUINONES.Patent dated October 7, 1941. Disclaimer filed May 26, 1942, by theassignee, Society of Chemical Industry in Basle. Hereby disclaims alkyl,cycloalkyl and aralkyl radicals from the scope of the definition of R inthe first paragraph of the specification of the said patent;

Hereby disclaims the subject matter of the last paragraph of Example 1of the said patent; and

Hereby disclaims from the scope of each of claims 1, 2, and 3 allcompounds cor responding to the formulae of the said claims wherein an Ris an alkyl, cycloalkyl or aralkyl radical.

[Oflicial Gazette June 28, 1.942.]

